The children accuse Winston of committing?

A rather vague question. In the novel "1984", there were two children of Winston Smith's neighbor who accused him of "thoughtcrime", but it was done in a somewhat joking manner, and was only a yelled accusation, accompanied by a physical assault with a toy slingshot. The children did not formally go to the Ministry of Love and turn in a report.

They did turn in their father, though. For saying, "Down with Big Brother" in his sleep. It is unclear as to whether the father, Parsons, really did that, but he said he was proud of them for doing their duty.